It may sound like pure coincidence but after I introduced Herpes (who is a male) with Derp her lump size was cut to about 1/4 the size it used to be. We also changed her food and now I think she is fat and happy! The other fish they are with leave them alone and the two frogs get along great! That as about the only thing I changed. Hope that helps at all. I can take pictures tomorrow and let you know what food they get.